Google Gadgets are tiny little applications on- News, tools, communication, fun& games, finance, sports, lifestyle and technology. It’s diverse and covers from simple Google map to sophisticated NOAA satellite images.
Previously they were only available for Google Desktop or Google Homepages, but on October 3, 2006 Google announced Google Gadgets are now open for using in any WebPages including blogs. With almost no effort and at no cost, webpage owners can add complex, dynamically updating content to their own websites using Google Gadgets.
To bring up interactivity or useful information Google gadgets can b used in blogs. But needless to remind that relativity is important things to consider before adding any Gadgets. For example- You have a blog on search engine optimization and you are using NOAA radar gadgets, will simply make your blog ugly.
Since Google Gadgets codes are simple HTML (that’s what Google says, but I found only JavaScript’s), it will be easy to integrate as widget in you sidebar even.